I can confirm the issue exists with 2016 Pro Plus and that its directly related to Google File Stream. Through process of elimination, I started killing apps one by one and found that when I have File Stream disabled and open the file from email (downloading to the downloads folder) the file opens as expected with the "Enable Content" button. What's odd is that if I start file stream again, the file will continue to work (even after deleting and redownloading), but other files that have never been successfully opened start to fail again.
